Automatic damper.



A. W, ARNOLD.

AUTOMATIC DAMPER.

APPLICATION FILED JULY 27, 1912.

WITNESSES IIWE/VTOR THE NORR= ETERS Ca, PHOTQLITHOH WASHINGTUN, D. C,

Patented Mar. 23, 11915.

ARTHUR WILLIS ARNOLD, 0E MINNEAPOLIS, MINNESOTA.

AUTOMATIC DAMPER.

Specification of Letters Patent.

Application filed July 27, 1912.

To all 10710121 it may concern:

Be it known that I, ilRTHUR WILLIS AR- NGLD, a citizen of the United States, and a resident of Minneapolis, in the county of Hennepin and State of Minnesota, have in vented a new and Improved Automatic Damper, of which the following is a full, clear, and exact description.

This invention relates to automatic dampers or draft controllers of the type comprising one or more pivoted wings adapted to hang normally by gravity open in the path of the draft in a stove pipe or furnace flue and having means for varying the automatic closing operation of said wings according to the variations in draft in said pipe or flue, due either to outside wind influence or draft caused directly by variations in heat within the stove or furnace.

The present invention relates more particularly to certain details or refinements of construction whereby the adjustments of the counterbalance means may be more satisfactorily effected, and whereby the damper as a whole is rendered more satisfactory and reliable in use than heretofore.

The foregoing and other objects of this invention will hereinafter be fully described and claimed and illustrated in the drawings accompanying this specification in which like characters of reference indicate corresponding parts in all the views, and in which- Figure 1 is a perspective view of the device with the parts in normal operative position, the damper wings being set for a moderate fire; Fig. 2 is a front elevation of a fragment of the device, particularly the means for locking the damper opening; and F 3 is a perspective detail of the combined bumper and counterbalance support.

Referring to the drawings 1 show at 10 any suitable construction of collar or pipe section which is to be understood as constituting a support in which the wings 11 are pivotally mounted on pivot rods 12. lit will be understood that the collar 10 may represent a section of a fine to which the Wings 11 are pivoted, or it may represent a separate element as a permanent part of the damper construction. On the front ends of the pivot rods are rigidly secured in any suitable manner a pair of arms 13, the same being crossed so that a downward pull upon the arms will cause them to separate and Patented llllar. 23, 119115.

Serial No. 711,805.

lift the wings 11 toward their closed posit1on. The counterbalance which I show in this instance comprises a flexible chain member 14 comprising a comparatively short heavy section M and a light section 14. 4 ihe upper end of the section 14 18 connected by means of a pair of short flexible connections such as chains 15 to the opposite ends of a cross bar or spreader 16. The spreader is pivotally connected with the ends of the arms 13 by means of a pair of links 17, each link having an eye at each end which is adapted preferably for permanent connection to its respective part. The opposite free end of the light chain section 1 f is provided with a loop or ring 14 whereby it may be more easily manipulated. I

From the construction so far described it will be understood that when a minimum amount of fire is desired in the stove or furnace, or, in other words, when it is desired to maintain the damper practically shut, as for instance, during night service or'when banking, the counterbalance shown will be lowered so as to bring the major portion of the section 14? with its weight suspended directly from the spreader and the damper arms. The weightof the section 1-? should therefore be calculated to approximately counterbalance the weight of the wings. When, however, it is desired to provide draft for ahotter fire, the lower end of the heavy section 14? will be looped up to a greater or less extent by hooking up the lighter section 14 upon any suitable support, thereby relieving the wings from the weight of so much of the section 1% as has been looped up, as above indicated. It is also to be noted that when the damper wings approach their closed position, the levers 13 and spreader 16 descend. Certain of the links of the counterbalance chain, therefore, automatically transfer their heft from one side of the loop to the other and become supported from the fixed support. The effective heft or influence of the counterbalance, therefore, becomes reduced while the damper wings are ascending, presenting larger surfaces to be acted upon by the force of the draft; hence, to a certain extent there is a tendency, due to the automatic shift of ef fective heft of the counterbalance, for the damper wings to become retarded in their movement as they approach the closed position regardless of the fact of the exposure of a greater surface to the force of the draft. lVhen such weight is relieved from the wings they will gravitate toward their open position to an extent proportional to the amount of weight taken therefrom. By the use of the section l-Ti of the small gage chain, the entire device presents neater appearance and is both cheaper and lighter in con struction and for transportation than if the entire chain had only one character of link. Again, the lighter chain section 14 having shorter as well as lighter links provides for a more delicate adjustment or variation in effective heft of the counterbalance than if only one character of link was employed.

. The section 14: may be of any suitable length and extends upwardly for cooperation with a fixed support to be located at any convenient place. As shown, however, as a convenient type of support, I provide a com bined bumper and counterbalance support 18. This support is made preferably, though not necessarily, of a single blank of sheet metal and comprises a portion 18 substantially fiat and having a hole 18* therethrough through which the lighter chain section 14 passes, but the hole is of less diameter than the diameter of the ring 14, whereby the ring serves to retain the chain in permanent connection with the support' The rear portion of the support 18 is provided with laterally extending bumper stops 19 which are adapted to be bent up vardly at their outer ends more or less so as to vary the throw of the arms 1.3 and thereby variably limit the extent of closing movement of the wings.

Extending downwardly at an angle from the rear edge of the portion 18 is a bracket portion 20 through which the support is adapted to be secured as by a rivet or the like to the collar 10, and the lower portion of said bracket is formed into an upwardly extending hook 21 into which the spreader 16 is adapted to be placed, as shown in Fig. 2, when it is desired to lock the damper wings open temporarily. The vertical plane of the hook, however, is at the rear of the normally vertical plane of the spreader so that there is no danger of the spreader becoming accidentally caught by said hook during the normal operation of the damper. At the front'part of the support there is formed an upwardly extending fork 22 adapted to receive the chain section 14- and hold it in any desired position of adjustment by the interlocking of any link of said chain section in the fork.

The several parts of the device may be made of any suitable materials and the relative sizes and proportions of the several parts may be varied to a considerable extent without departing from the spirit of the invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

i. In an automatic damper, the combination of a wing, a counterbalance for the wing comprisin a chain having sections of cooperating with the lighter chain section.

3. In an automatic damper, the combination with a pair of wings and arms connected to said wings, of a counterbalance for tile wings comprising a spreader connected to the arms, and a single chain suspended from both ends of said spreader, and a fixed support cooperating with said chain, whereby the effective heft thereof will be varied.

4;. In an automatic damper, the comhination of a pair of pivoted wings, a pair of arms connected to said wings, a. counterbalance for the wings comprising a spreader, and a single chain having one end connected to the ends of the spreader, said chain comprising a heavy section and :1 lighter section having shorter links than the heavier section, and a fixed support for cooperation with the links of the lighter chain section.

5. In an automatic damper, the combination of a pair of wings, a pair of arms rigidly connected to the wings for controlling their movement, a counterbalance connected to the arms for operation thereof in one direction, and a bumper adapted to control the extent of movement of the arms when acted upon by the counterbalance, said bumper also including a fixed support for cooperation with the counterbalance, whereby the effective heft thereof may be regulated.

6. In an automatic damper, the combination of a pair of wings, a pair of arms connected to the wings, a counterbalance connected to the arms to operate the same in one direction, and a combined bumper and countel-balance support comprising a pair of stops to limit the movement of the arms aforesaid and having a vertically extending fork for coiiperation with the counterbalance.

7. in an automatic damper, the combination of a pair of wings, arms connected to the wings, a spreader connected to the ends of the arms, a counterbalance comprising a single chain having one end connected to said spreader, and a combined bumper and counterbalance support having a pair of stops for the arms, a hook for coiiperation with said spreader to lock the damper open, and a vertically extending fork for cooperation with any link of said chain remote from the end connected to the spreader.

8. The herein described combined bumper and counterbalance support for automatic dampers comprising a unitary structure having laterally extending stops, a downwardly extending bracket on one side having an upturned hook and having on the other side an upwardly extending fork, that portion of the device adjacent the fork having a vertical hole, substantially as set forth.

9. In a draft operated damper, the combination of a damper member, mounted to swing, a counterbalancing chain comprising sections of different weights attached to said member, and a support having means to which the free end of the chain is adjustably connected, said support adapted to receive portions of said chain successively as the damper member swings from open to closed positions whereby the effective influence of the chain upon the damper member is varied inversely to the effective force of the draft upon said member.

10. In a draft operated damper, the combination of a pipe section having dampermembers mounted to swing therein, external arms for said dampers, a spreader secured to the arms, a counterbalancing chain comprising a heavy and a light section, said heavy section being secured to said spreader, a bumper for said arms, and a fixed support having means to which the light section of said chain is adjustably attached; said support being adapted to receive portions of said chain successively as the damper swings from open to closed positions whereby the effective influence of the chain upon the damper members is varied inversely to the effective force of the draft upon said memhere.

11. In a draft operated damper, the combination of a pipe section having two spindles freely mounted therein, damper members rigidly secured to said spindles, arms rigidly and externally secured to said spindles, a spreader having links to connect the spreader to said arms, a counterbalancing chain comprising a heavy and a light portion, said heavy portion being centrally suspended from said spreader, a combined bumper and support fixed on said pipe section having forked means to which the light section of said chain is adjustably attached, said support also provided with a hooked member adapted to receive saic spreader to lock said damper members in the open draft position.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ARTHUR WILLIS ARNOLD.

YVitnesses:

F. E. ARNOLD, J. D. SHo'rwELL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, 11). G. 

